Automatic fuse-changer



1933- R. R. PITTMAN ETAL 1,894,056

AUTOMATIC FUSE CHANGER Filed April 2, 1952 3 %eets-Sheet 1 Q%% 52 By. Z

INV ENTO I. m all M 1933. R. R. PITTMAN ET AL 1,394,056

AUTOMATIC FUSE CHANGER Filed April 2, 1932 3 Sheets-Sheet 2 Jam 10, 1933.

R. R. PITTMAN ETAL. 56

AUTOMATIC FUSE CHANGER Filed April 2. 1932 5 Sheets-Sheet 'Patentecl Jan. 10, 1933 UNITED STATES PATENT OFFICE I RALPH R. PITTMAN AND CARROLL H. WALSH, OF PINE BLUFF, ARKANSAS AUTOMATIC FUSE-CHANGER Application filed April 2, 1932. Serial No. 602,868.

This invention relates generally to protective devices for electrical circuits, and particularly to fusible devices used for preventing the passage of excess currents through said circuits, and has for its principal object the provision of means for automatically restoring the continuity of a circuit interrupted by the operation of a fuse through the replacement of the blown fuse by an auxiliary w fuse.

Another object of the invention resides in the novel arrangement of parts whereby the time required for the restoration of service over the circuit interrupted by a blown fuse is reduced to a minimum. In connection with the operation of overhead distribution lines, it is now well known that a large percentage of the total faults are caused by lightning flash-overs of such a character that the parts flashed are not permanently damaged. Such faults cause a short interruption to' service, and certain synchronous equipment is stopped. It is an object of this invention to provide means for reducing the time of the intime interval than that provided by any other means known to us.

A further object of this invention is to provide a simple, inexpensive and effective device for the purpose above described. 7

With the above and other objects in view which will appear as the description proceeds, our invention resides in the novel construction, combination and arrangement of parts as hereinafter described and more particularly defined by understood that such changes as come within the scope of the claims may be made in the embodiment herein disclosed.

In the drawings, Figure 1 is a front elevational view of the device.

Figure 2 is a side elevational view of the device Figure 3 is a side elevational view of a tripping plunger assembly, shown partly in section.

Figure 4 is an end view of a tripping plunger assembly.

terruption to a value of the order of onetenth of a second, which is a much shorter the appended claims, it being Figure 5 is a front elevational view of a tripping plunger assembly.

Figure 6 is a front elevational view of the latching assembly.

Figure 7 is an end view of the latching assembly.

Figure 8 is a side latching assembly.

Figure 9 is a front elevational view of the hook member for supporting the fusible contact members.

Figure 10 is a plan view of the hook member for supporting the fusible contact memers.

Figure 11 is a plan view of the top fuse terminal and contact shown with the cap removed.

Figure 12 is a fragmentary elevational view of the top fuse terminal and contact, shown with the ca removed.

Figure 13 is a side elevational view of the device following its operation, and with one fusible contact member manuallg pulled down preparatory to removing same for refusing.

As shown by the assembly views illustrated by Figures 1, 2, and 13, the fuse-changer con-. sists generally of three upstanding fuses, supported by a pair of insulators. The central fusible contact member 11 is normally in the circuit, and the lateral fusible contact members 10 and 12 are supported in an auxiliary position external to the circuit. The se uence of operation of the particular em iment here shown is as follows: Upon the melting of the fusible element in contact member 11, contact member 10 moves to a position to close the circuit opened by .the melting of the fusible element in contact member 11. Following this action, upon the melting of the fusible element in contact member 10, the contact member 12 moves to the circuitclosing position.

Referring now more .invdetail to the assembly views illustrated by Figures 1, 2 and 13,- insulators 77 and 78-are rigidly attached to a supporting metallic base 79 by means of the cap screws 80.

Suitably secured to insulator 77 by means of the cap screws 81 'is a metallic plate 68 elevational view of the havin longitudinally extending arms and a latera ly extending arcuate portlon' adapted to substantially align with the metallic cap of insulator 78. On each longitudinally extending arm of plate 68 is mounted by means of cap screws 82 the bent metallicmember 67, consisting of a substantially square section of metal rod folded at the center portion to form a pair of parallel bars in spaced relation, the main portion of the folded section substantially normal to plate 68. One end of-the folded section of t e metallic member 67 is bent at right angles to the main portion to provide a surface for attaching the member 67 to the plate 68, and the other end is provided with an upwardly disposed end portion for providing a resilient mounting for the control contact clip 86, as by the cap screws 84.

The J-shaped metal strap 89 provides a terminal for a line wire at one end, and supports the contact clip 73 at the other end.

The metallic plate 47 is supported, as by the bolt 85, on insulator 78, and is shown more in detail in Figures 6, 7 and 8. Two pairs of extending portions of the plate 47 are bent to form short cylindrical extensions from the plate, each pair being adapted for formin one-half of a hinged joint at the lower slde of the plate. At" the other side of the plate are mounted the U-shaped trip ping rods 53 and 44, the tripping rod 53 bein supported on the front of the plate 47 by t e bearing 52, and the tripping rod 44 being supported on the rear of the plate 47 by the bearings 46.

For cooperating with the hinged portion of plate 47 is provided the two bent members and 65 having a bent cylindrical portion for forming a hinge with the extended ortion of p ate 47 and in addition a pair 0 downwardly and forwardly extending hooks. The pins 72, together with the extended portions of the plate 47 and the bent members 50 and 65 provide a means for .hingedly fixing the members to the plate 47.

The U-shaped springs 48 and 88 having, by means of thecap screws 83, one extremity of the U fixed to the plate 47 and the other extremity to the bent member 50, provides means for biasing the bent members 50 and 65 respectively in a clockwise direction away from the plate 47. The contact clips 49 and 63 are rigidly attached by some suitable means, as welding, to the bent members 50 and 65 respectively.

The plate 47, in addition to hingedly sup porting the contact clips 49 and 63 as above described,,also rigidly supports the central lower contact clip 62, and the flat extended bar 70, the latter providing a load terminal for the device.

The central contact member 11 comprises the tube of insulatin material 28, to each end of which is attached in some suitable manner, as by means of complementary threads, the upper contact 35 and the lower contact 29, adapted for cooperating respectively with the upper central contact clip 73 and the lower central contact clip 62. Adjacent the upper contact 35 are provided the hooks 75, biased by the spring 33 in a direction to latch the top of the contact member 11 in the cooperating contact 7 3. The eye 32 is adapted for operation by the usual type of insulated switch hook, and arranged so that a downward movement of the eye 32 raises the hooks 7 5, thus unlocking the contact member, for convenience in removing the contactmember 11 from the support. The top of the contact member is provided with a cap 34 for entirely closing the top of the contact member 11, and in addition as shown more in detail in Figures 11 and 12, b Y means of cooperating threads, and a slot 2 and the button 26 on the fusible element 25, provide means for tightly engaging the fusible element with the top contact 35.

A slotted metallic tube 57 shown in detail in Figures 3, 4 and 5 is rigidly attached to the rear of each of the lower contacts 29 and 37 by means of a flattened side of the tube 57, and screws extending through the respective lower contact 29or 37 into the flattened side of the respective tube 57 A plunger 55, also a metallic tube having an outside diameter somewhat less than the inside diameter of its slotted tube 57 extends therethrough, forming the inner tube concentric with the outer tube 57, and centered therein by the bushing 56. l The inner tube 55 is adapted for reciprocatory movement within the outer tube 57 and is guided and limited in its reciprocations by means of a pair of oppositely extending pins 59, the latter engaging the sides of the slot in the outer tube 57. The spring 58 is adapted to engage the pins 59, and in this manner the inner tube 55 is biased in an upward direction.

To better illustrate the assembly, Figures 3 and 4 have been drawn showing the spring 58 deformed following the downward movement of the inner tube 55.

A metallic cap 61 is provided for engaging the cooperating threads at the top of the inner tube 55 which is used in connection with the contact memberll (see Fig. 13), and for the further purpose of rigidly clamping the button 23 to the upper end of the inner tube 55, in this manner forming a lower terminal for the fusible element 25. The flexible conductor is provided for carrying the current from the fusible element 25 to the outer tube 57. rigidly fixedto the inner tube 55 which is used in connection with the contact member 10 for the purpose of laterally transferring the movement of the respective inner tube 55. The inner tubev 55, with the related members above described, forms a Ak 4.44 A

plunger biased in an upward direction by the spring 58, and arranged to be moved in a downward direction by means of tension on 'the fusible element 25 against the bias of the spring 58.

To insert a fusible element in contact member 11, the caps 34 and 61 are removed and the extended end of the fusible element 25, together with the top button 26 is first urged downwardly through the plunger 55 until the lower button 23 contacts the upper end of the plunger 55. p The cap 61 is then replaced in position on the upper end of the plunger 55. The extended end of the fusible element 25 is then urged in an upward direction through the insulating tube 28 until the end of the fusible element appears at the top of the tube. manually urged in a direction against the bias of the spring 58, this movement permitting the upper button 26 to be moved laterally and held in place by the slot 27. The

cap 34 is then replaced. Upon the comple-' tion of this procedure, the fusible element is sulnected to a tension due to the spring 58,

and the plunger 55 is biased to move in'an' upward direction upon the parting of fusib e element 25.

Assuming that contact member 11 has been properly fused as above described, and inserted in its cooperating contact clips, the

plunger 55 is now in position to strike but spaced from. the tripping rod 53 upon the parting of the fusible element 25.

Contact member 10 which is similar in construction to contact member 11 except for the addition of the yoke shown in Figs. 3, 4 and 5, is then inserted in the hooks of the bent member 50, and swung against the bias of the spring 48 until it is latched in a substantially vertical auxiliary position, wher'e' it is held by the action of the hook 51 of tripping rod 53 dropping over-the 11 per portion of bent member 50, as shown in igure 2.

It is now apparent that the parting of fusible element 25' due to any cause, as excessive current therethrough, will release the plunger 55, the latter moving upward under I the bias of the spring 58. The impact of the plunger 55 rotates the tripping rod 53 in its aring 52, raising the hook 51 and in this manner disengagin the hook 51 from the bent member 50. The latter member then rotates the entire lower contact assembly including the contact clip 49 .member 10 about the pivots 72. Since the of the contact contact member 10 is fixed in position by the 1 contact clip 49 and the pins 38 engaging the hooks 50, the contact member is swung under the bias of the spring 48 from the vertical auxiliary position shown in Figures 1 and 2, to the circuit closing position shown in Figure 13.

The movement of the contact member 10 from the auxiliary position to the circuit At this point, the plunger 55 is closing position is definitely guided between the parallel bars 67 to enga the contact4l with the contact clip 86. The latch assem bly above described prevents the passa e of the contact 41, through the clip 86, an the impact due to the latchin action is absorbed by the resilient design oft e bent guiding bar member 67 Upon the completion of the movement of contact member 10 from the vertical auxiliary position to the circuit closing position, the spring biased plunger 55 similarly attached to contact member 10 is in osition to engage trippin rod 44 throu h t e yoke 45 assembled on the tripping p unger of said contact member 10.

The contact member 12 is adapted to be supported in a vertical auxiliary position in the same manner as that described with reference Obviously any number of fusible contact members may be used through the addition of a tripping rod, a cooperating tripping plunger, and a cooperating contact c ip su rt for each additional contact member. owever, actual experience indicates that more than two reclosures are seldom required, and that one reclosure will restore service in about eight percent of the faults occurring on overhea lines.

The device here disclosed operates in a very much shorter time than any with which we are familiar, due to the novel method employed in supporting the auxiliary contact members in a position without the circuit, and the new method of supporting the lower contacts of the contact members in the cooperating clips, so that no motion of the lower contacts is required with reference to the. cooperating clips.

It will be noted that provision has been made for entirely closing the upper end of the contact members, as it. is very undesirable to expel the flame due to the action of a fuse in an upward direction toward apparatus or live conductors. The flame attending the ially one of the exblowing of a fuse, es pulsion type, is high y conducting, and devices arranged for expelling flame in an upward direction toward line conductors often produce disastrous short circuits.

The positive means for guiding the movable contact members is also new, and makes possible a fuse-changing device for the higher voltages which necessarily require longer fuse tubes. I

The action of this device, while very simple and positive, is substantially free from impact, due to the novel design of the members supporting the auxiliary contact clips,

and this consideration makes possible a very initiate the operation of the auxiliary contact members.

From the foregoing description taken in connection with the accompanying drawings, it will be apparent to those skilled in the art that we provide anovel and improved automatic fuse-changer for the purpose described.

\Vhat we claim as our invention is:

l. A repeating fuse adapted for inst-allation in a circuit, comprising in combination insulating means supporting a fixed fuse-containing tube of insulating material and a plurality of movable fuse-containing tubes of insulating material, means for latching said movable tubes in a normal position out of the circuit, springs biasing said movable tubes to an operating position in the circuit, and unlatching means for said movable tubes including a fusible element under tension and means biased thereby, whereby the rupturing of the fuse in the said circuit effects the sequential actuation of the said movable tubes from said normal position to said operating position.

2. In a fused disconnecting device adapted for installation in a circuit, a pair of insulators supporting a fixed fuse-containing tube of insulating material and a plurality of movable fuse-containing tubes of insulating material, a base supporting said insulators, means for latching said movable tubes in a normal position out of said circuit, springs biasing said movable tubes to an operating position in said circuit, unlatching means for said movable tubes including a fuse under tension and a spring biased thereby, whereby the rupturing of said fuse in the said circuit permits the sequential actuation of the said movable tubes from said normal position to said operating position, and means including substantially parallel metallic contact-carrying bars for guiding said movable tubes from said normal to said operating position.

3. In a fused disconnecting device adapted for installation in a circuit, a pair of insulators supporting a fixed fuse-containing tube of insulating material and a plurality of movable fuse-containing tubes of insulating material, a base supporting said insulators, means for latching said movable tubes in a normal position out of said circuit, springs biasing said movable tubes to an operating position in said circuit, unlatching means for said movable tubes including a fusible element under tension and a spring biased thereby, whereby the rupturing of the fuse in the said circuit permits the sequential actuation of the said movable tubes from said normal position to said operating position, and impact absorbing means including an arcuate resilient contact-carrying member.

4. In a circuit disconnecting device, in combination, fuse-containing contact members swingably disposed for movement in a direction toward cooperating contact members to close the circuit through a fusible element within said contact members, a trip mechanism including a spring-biased plunger forming one terminal of said fusible element, and means including a spring biasing said contact members for controlling the speed of movement of said Contact members to the said cooperating contacts.

In a circuit disconnecting device, in combination, a pair of insulators supporting a plurality of fuse-containing tubes of insulating material having contacts adjacent the ends thereof, one of the said tubes being fixed in cooperating contacts in the circuit, and the remainder of said tubes swingably movable to cooperating contacts, means for latching said movable tubes in a normal position Without the circuit, springs biasing said movable tubes to said cooperating contacts in said circuit, unlatching means adjacent the one end of said movable tubes including a spring-pressed movable plunger forming a terminal for one end of said fuse, and a cap for closing the other end of said movable tubes.

6. In a circuit disconnecting device, in combination, spring-pressed contact members swingably movable to cooperating contacts to close the circuit through a fusible element, and means including substantially parallel metallic guiding bars supporting said cooperating contacts for controlling the elapsed time for the movement of said contact members to engagement with the said cooperating contacts.

7. In a circuit disconnecting device, in combination, spring-biased contact members swingably movable to cooperating contacts to close the circuit through a fusible element, said cont-act members comprising a tube of insulating material having an upper contact and a lower contact adjacent the ends thereof, a fusible element Within said tube connecting said contacts, a stationary contact for cooperating with said upper contact, and a hingedly fixed contact for cooperating with said lower contact, whereby the said tubes may be swingably urged for the engagement of the contacts mounted thereon with said cooperating contacts Without motion of said its lower contact with respect to said hingedly fixed contact.

8. A circuit disconnecting device comprising, in combination, a support for a plurality of tubes of insulating material having an upper contact and a lower contact adjacent the ends thereof, a fusible element within said tube connecting said contacts, stationary upper contact clips for cooperating with said upper contacts, hingedly mounted ower contact clips for cooperating with said lower contacts, and means including a spring for urging said tubes to engage said upper contacts with said stationary contact clips, and means including a pair of hooks and a cooperating pivot adapted for rotation in said hooks for manually removing said tubes from said support.

9. In a repeating fuse, a plurality of pivoted fuse-containing tubes of insulating material having contacts adjacent the ends thereof, a spring biasing certain of said tubes to fixed cooperating contact cli s for closing a circuit, a latch restraining t e movement of certain of said tubes, and unlatching means including a spring-pressed plun er and a fuse connected to said plunger and restraining the movement of said lunger.

10. A circuit switching device comprising, in combination, a plurality of upstanding contact members, said contact members comprising tubes .of insulating material having an upper contact and a lower contact adjacent the ends thereof, a fusible element within said tubes connecting said contacts; stationary resilient upper contact clips for cooperating with said upper contacts, hinged supports for certain lower contact clips for cooperating with certain of said lower contacts, a spring rigidly fixed to said hinged support biasing said contact member to engage said upper contact clips to close the circuit through said fusible element, means including a hook cooperating with said hinged support for latching certain of said contact membersin an upstanding position, and unlatching means adjacent the lower end of said contact members including a springpressed movable plunger forming a terminal for one end of said fusible element.

11. A circuit switching device, having, in combination, a first removably member comprising a tube of insulatin material having an upper contact and a Iower contact adjacent the ends thereof for cooperatin with fixed contact clips to close the circuit t rough a fusible element extendin through said tube and connecting the said contacts, a metallic cap adapted for attaching to the upper end of said first contact memher for entirely closing the opening at the upper end of said tube and forming an upper terminal for said fusible element, a hollow spring-biased dplunger having laterally extending pins a, apte for reciprocatory movefixed contact ment and guided in its reciprocationsabiy a i slottedimetallic housin rigidl fixed cent the lower contact oIsaid tu a metallic cap adapted for attaching to one end of said lunger forming a lower terminal for said usibe element; a second contact member comprising a tube of insulating material having an upper contact and a lower contact adjacent the ends thereof, a lower contact clip for cooperating with said lower contact suported by a hinge, a spring fixed to said inge biasing said contact member to enga e a resilient cooperatin contact to close said circuit through a fusfiile element contained in said second contact member, latching means for said second contact member including a U-shaped rod having a hook on one arm of the U for engaging said hinge and restraining the movement of the second contact member, a hinged support for said U-shaped rod and means for supporting the other arm of said U-shaped rod in position to engage said movable plunger mounted on said rst tube whereby the said-second'contact member is actuated to close the circuit through the fusible element contained therein upon the passage of an excess current through the fusible element in said first contact member to restore the continuit of said circuit without movement of said rst contact member with respect to said fixed contact clips.

12. In an automatic fuse-changer, comprising support and a plurality of fuse-con taining insulating tubes having contacts adjacent the ends thereof, a fusible element connecting said contacts, means including a spring-biased movable metallic plunger fixed to said insulatin tubes forming one terminal of said fusibfiz element for'exerting tension on said fusible element, and a latch o rable by said plunger for latching said tube; in a definite position on said su port, whereby a substantially fixed len h of fusible element is required to latch sai tube in said definite position.

In testimony whereof we aflix our signatures.

RALPH R. PITTMAN. CARROLL H. WALSH. 

